[gnome-calendar] utils: add autoptr support for ESource

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit caffb60065217e4ddde35eae044c1c882a845793
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Wed Nov 8 23:25:59 2017 -0200

    utils: add autoptr support for ESource

 src/gcal-utils.h |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/src/gcal-utils.h b/src/gcal-utils.h
index 1ed7547..3b5bd9a 100644
--- a/src/gcal-utils.h
+++ b/src/gcal-utils.h
@@ -34,6 +34,9 @@
 #define gcal_clear_datetime(dt) g_clear_pointer (dt, g_date_time_unref)
 #define gcal_clear_timeout(pp) { if (pp && *pp) { g_source_remove (*pp); *pp = 0; } }
 
+/* Add autoptr support for libecal */
+G_DEFINE_AUTOPTR_CLEANUP_FUNC (ESource, g_object_unref)
+
 /**
  * GcalWindowViewType:
  * @GCAL_WINDOW_VIEW_DAY: Day view (not implemented)